After losing nose tackle Vince Wilfork to a season-ending injury, the focus has shifted to defensive tackles like Tommy Kelly, Joe Vellano and others who will be asked to fill the void.

As for the Patriots' upcoming opponent, the Cincinnati Bengals, their big men present a grueling first (or second) challenge post-Wilfork.

Passing downs, 2013

Team

Plays

Sacks

Hits

Hurries

Total pressures

Pressure %

Bengals OL

162

0

6

21

27

16.7

Patriots DL

172

9

17

33

59

34.3

ProFootballFocus.com

According to Pro Football Focus (subscription required), the Bengals are the NFL's best offensive line in pass-blocking efficiency. They have allowed pressure on quarterback Andy Dalton on just 27 of his 162 dropbacks. Dalton has been sacked seven times, but PFF doesn't assign blame to the offensive line for any of those sacks.

The Bengals have not run the ball particularly well this year, averaging just 3.4 yards per carry on the season, but they have a big offensive line that can open holes up front; PFF grades them as the eighth-best run-blocking offense in the NFL through four games.

The Patriots, on the other hand, have created pressure 59 total times on 172 total dropbacks and have yielded 4.1 YPA rushing. Wilfork himself was only responsible for three of those quarterback pressures, but his ability to draw double-teams helped open things up for his teammates.

"Obviously, somebody is going to have to replace him," Patriots head coach Bill Belichick said Wednesday, "but, collectively, as a team, we're all going to have to pull together. There's no one person that can replace Vince Wilfork."

Things get especially tricky for the Patriots' interior defensive line, which is faced with two guards in Kevin Zeitler and Clint Boling who are tough as nails. PFF rates both among the top six guards in the league this year.

Zeitler and Boling stand at 6'4" and 6'5", respectively, and each weighs in at over 310 pounds. Combined, the two provide plenty of holes for the running backs to hit.

On this particular play, the Bengals ran a draw up the middle against the Packers. The Bengals came out in a spread formation, with Dalton in the shotgun and running back Giovani Bernard at Dalton's right hip. With four receivers out wide, the pressure was on the offensive line to get their blocks and spring Bernard to the second level, where the defense was weak.

A solid push up the middle from Zeitler, Boling and center Kyle Cook gave Bernard all the room he needed to go 17 yards. The Bengals scored on the next play.

Unless the Patriots load the box or send five men crashing the line of scrimmage, someone on the Patriots defensive line will draw a double-team—that's the nature of the five-on-four numbers game of the offensive line vs. the defensive line. How effective will that player be when staving off two blockers, though? That's the million-dollar question.

The Bengals, however, are preparing for the best against whomever is lining up across from them on Sunday.

"Every player has strengths, so we're going to have to take away his strengths and make him play to his weaknesses," said Bengals running back BenJarvus Green-Ellis. "But obviously, like I said, you never can replace a Vince Wilfork, not in the middle of the season like this. But the other guys, the young guys that they have are doing a good job when he’s not in of coming in and playing well as well."

Those young guys include the likes of Vellano and Chris Jones, who each played a bigger role than expected against the Falcons, combining for 52 defensive snaps (33 for Vellano, 19 for Jones).

Vellano flashed a familiar Wilfork ability when he was used as a two-gap defensive tackle against the Falcons. He held his own in a one-on-one situation, getting leverage on the blocker and keeping his eyes on the running back, Jason Snelling. Once Snelling picked a hole, Vellano shed his blocker and made the arm tackle.

There's pressure on the defensive tackles to fill the void and carry out some of Wilfork's responsibilities, but there's also pressure on defensive ends Chandler Jones and Rob Ninkovich to continue to play at a high level when the focus is on them. Jones lined up next to Wilfork on a consistent basis and may be given a bit more attention now that Wilfork is no longer in the picture.

"Every week, we go in looking at what other teams do against us," said Ninkovich. "We know that having [Wilfork] out of the game is going to be a difference, and maybe teams are going to attack us differently, but we really don't know yet."

They'll have a much better idea once they take the field on Sunday, but the result could be a chain reaction that spreads throughout the defense. Thus, instead of the burden falling on one guy, it's up to each player individually to raise their level.

If they're up to this challenge, they may be up to just about any challenge that they will face this season.